hwtracing/coresight/coresight-trace-id.h

1 /* SPDX-License-Identifier: GPL-2.0 */
13  * With multi cpu systems, and more additional trace sources a scalable
19  * In order to ensure that a consistent cpu / ID matching is maintained
20  * throughout a perf cs_etm event session - a session in progress flag will
22  * complete. This allows the same CPU to be re-allocated its prior ID.
28  * API permits multiple maps to be maintained - for large systems where
55  * @pend_rel_ids: CPU IDs that have been released by the trace source but not
56  *		  yet marked as available, to allow re-allocation to the same
57  *		  CPU during a perf session.
67  * Read and optionally allocate a CoreSight trace ID and associate with a CPU.
69  * Function will read the current trace ID for the associated CPU,
75  * @cpu: The CPU index to allocate for.
77  * return: CoreSight trace ID or -EINVAL if allocation impossible.
79 int coresight_trace_id_get_cpu_id(int cpu);
82  * Release an allocated trace ID associated with the CPU.
84  * This will release the CoreSight trace ID associated with the CPU,
90  * @cpu: The CPU index to release the associated trace ID.
92 void coresight_trace_id_put_cpu_id(int cpu);
95  * Read the current allocated CoreSight Trace ID value for the CPU.
97  * Fast read of the current value that does not allocate if no ID allocated
98  * for the CPU.
100  * Used in perf context  where it is known that the value for the CPU will not
102  * for the CPU as a packet in the data file. IDs cannot change during a perf
108  * @cpu: The CPU index to read.
112 int coresight_trace_id_read_cpu_id(int cpu);
117  * Unconditionally allocates a Trace ID, without associating the ID with a CPU.
121  * return: Trace ID or -EINVAL if allocation is impossible.
139  * Increase the perf session reference count - called by perf when setting up
143  * associated with a CPU cannot change or be released during a perf session.